General Impact
Rabbits cause severe damage to the natural environment and agricultural areas. They compete with native wildlife for food and shelter, and contribute to a decline in the numbers of many native plants and animals. They can also enhance negative impacts on native species by supporting large populations of predators such as cats and foxes. They cause extensive erosion through browsing and loss of plant cover and often destroy the habitat of many small animals. Rabbits also compete with livestock for food (Courchamp et al. 2003; Norbury and Reddiex, 2005).
Location Specific Impacts:Macquarie Is. (sub-Antarctic) (Australia) 
Economic/Livelihoods: Loss of tourism value. A landslide believed to be caused by heavy rabbit grazing in September 2006 adjacent to Sandy Bay staircase forced the closure of the staircase, boardwalk and Royal penguin viewing platform (key visitor infrastructure) (Tasmania National Parks Association Inc. 2006).
Ecosystem change: Rabbits, rats and mice are causing extensive impacts on the biodiversity and landscape of the Macquarie Island Nature Reserve (Parks and Wildlife Service 2006). Rabbits are key drivers of ecosystem change. The drive at least two key threatening processes on Macquarie Island; one is their impact on vegetation (tall tussock grassland and herbfields), the second is their alteration of valuable seabird habitats via increasing soil instability and erosion processes (Parks and Wildlife Service 2006). Rabbits are known for their ability to heavily graze vegetation, destroyed some tall tussock grassland areas and converting them to short grassland or mire (Copson 1984, Scott 1988, in Parks and Wildlife Service 2006). Some plant species, such as Pleurophyllum hookeri and Stilbocarpa polaris, are so heavily grazed by rabbits that they have become locally extinct from some sites on the island (Parks and Wildlife Service 2006).
It is thought that habitat alteration by rabbits, as well as predation by skuas and introduced cats, wekas and rats, have greatly reduced or even eliminated populations of some of the smaller species of prion and petrel which once bred in the reserve (Brothers 1984, Brothers and Copson 1988, in Parks and Wildlife Service 2006).
Soil stability is a key environmental variable in the Macquarie Island Nature Reserve which is affected partly by rabbit grazing, and also by continual winds, seismic activity, freezing and thawing and constant precipitation (Parks and Wildlife Service 2006).
Habitat alteration: In Sandy Bay Healthy green tussock vegetation is being replaced by dead brown stumps due to rabbit grazing (Tasmania National Parks Association Inc. 2006).
Physical disturbance: Macquarie Island’s largest king penguin (see Aptenodytes patagonicus in IUCN Red List of Threatened Species) colony, found at Lusitania Bay, was threatened by a landslide which occurred in September 2006 and which was thought to be due to a combination of heavy rainfall and rabbit grazing which increased the instability of the land. The landslide buried some penguins alive and destroyed part of the colonies habitat (Tasmania National Parks Association Inc. 2006). Kerguelen Is. (sub-Antarctic) (French Southern Territories) 
Habitat alteration: The impact of rabbits on Kerguelen has been studied. Rabbits have transformed the vegetation through herbivory, by digging burrows and accelerating erosion processes (Chapuis et al.,1994).
Reduction in native biodiversity: Ancient stands of two dominant endemic species, Pringlea antiscorbutica and Azorella selago have become rare and endangered. The elimination of these native species has also been reflected in an increase in the cover of introduced species. Rabbits also affect breeding birds, including Procellariidae, by destroying their breeding sites (Chapuis et al., 1994). Norfolk Island
Herbivory: The average rate of extinction of plant species between 1830 and 1977 was approximately one species every 10 years (Fullager 1978).
Interaction with other invasive species: Rabbits can also become additional food for animals such as cats, enabling these predators to increase their numbers and thus eat more native animals, including lizards and birds. This is an example of a flow-on effect, where the introduction of one problem animal results in an increase of another invasive species already established.
Physical disturbance: Extensive soil erosion frequently follows the loss of plant cover that results from browsing by rabbits. Ascension Is. (Saint Helena)
Reduction in native biodiversity: There are suggestions that rabbits may be affecting the ability of smaller sea bird species to recolonise the island (Pickup, 1999 in Varnham, 2006).
Threat to endangered species: Rabbits are affecting re-establishment of the 'Critically Endangered (CR)' endemic Ascension Spurge (see Euphorbia origanoides). Rabbits have affected attempts at re-establishment of this plant by grazing and digging at the base of plants, possibly to feed on the roots. Similarly rabbits are affecting establishment of new colonies of the 'Near Threatened (NT)' fern (see Marattia purpurascens). Saint Helena
Agricultural: Rabbits are an important agricultural and horticultural pest on St Helena. Farmers have reported almost total loss of crops by rabbit browsing (Bell & Boyle, 2008) and horticultural production at Longwood and Sandy Bay has suffered up to 100% losses of young plants. Rabbits also graze pasture which reduces food for sheep and other livestock (Miller, 2008).
Interaction with other invasive species: Rabbits have important predator-prey interactions with other invasive species on St Helena such as feral cats and rats. High rabbit numbers help maintain high predator numbers. Rabbit numbers are particularly high on two of the best habitats of the 'Critically Endangered (CR)' endemic wirebird (see Charadrius sanctaehelenae) on St Helena . As a result feral cats, which predate wirebirds, are also found in high numbers (Bell & Boyle 2008). Control of rabbits may result in prey switching of feral cats and rats to native species.
Reduction in native biodiversity: Rabbits threaten the five endemic plant species on St Helena through browsing, and are particularly damaging to young native plants growing in drier coastal zones (Miller 2008). Laysan Is. (United States (USA))
Herbivory: Between 1903 and 1923 (when they were eradicated) rabbits apparently eliminated 26 species of plants, a rate of loss exceeding one species per year (Christophersen and Caum 1931). A subsequent visit by Lamoureaux (1963) indicates that not all of these species became extinct on Laysan Island; presumably regeneration from seed had been possible. The vegetation was severely damaged. In 1923 the island was ‘a barren waste of sand with a few stunted trees’, only four of 26 plant species could be found, and three land birds had died out.
Interaction with other invasive species: Rabbits can also become additional food for animals such as cats, enabling these predators to increase their numbers and thus eat more native animals, including lizards and birds. This is an example of a flow-on effect, where the introduction of one problem animal results in an increase of another invasive species already established.
Physical disturbance: Extensive soil erosion frequently follows the loss of plant cover that results from browsing by rabbits.
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